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GB System Voltage Excursions - FY1920

  • GB System Voltage Excursions - FY1920

    The National Grid Electricity System Operator (ESO) publishes an annual report on the performance of the National Electricity Transmission System in Great Britain and fulfils Transmission Licence Standard Condition C17: Transmission System Security Standard and Quality of Service.

    The Electricity Safety, Quality and Continuity Regulations 2002 permit variations of voltage not exceeding 10% above and below the nominal at voltages of 132kV and above and not exceeding 6% at lower voltages. Any voltage excursions in excess of 15 minutes will be reported.

    The Grid Code reflects these limits, and imposes a further constraint for the 400kV system in that voltages can only exceed +5% for a maximum of 15 minutes. Reportable excursions may be either at the HV and/or LV of a connection point with a Grid Code User.

    This dataset shows all reportable voltage excursions till date in 2019/2020 based on C17 reporting criteria.

Table Information

Incident date and time

Title Incident date and time
Type datetime
Description Gives the date and time of the start of the excursion in Dth MONTH YEAR, HH:MM format.
Example 1st June 2018, 13:56

Incident Location

Title Incident location
Type string
Description The location in the UK where the excursion occurred.
Example -

Nominal Voltage (kV)

Title Nominal voltage (kV)
Type number
Description The voltage that would have been measured if there was no excursion.
Example 132
Unit kV

Maximum Voltage (kV)

Title Maximum voltage (kV)
Type number
Description The maximum voltage reached during the excursion.
Example 900
Unit kV

Duration (Minutes)

Title Duration (Minutes)
Type number
Description The length of time for which the voltage was deviated from statutory limits.
Example 10
Unit minutes